Methods, arrangements, and structures related to the technical field and character mentioned above are known earlier in a number of different embodiments.
With regard to electrically propellable vehicles, the latter can to advantage be categorized as “railbound vehicles” or as “non-railbound vehicles”.
“Railbound vehicles” are driven along their stretch of the roadway and roadway sections on parallel rails disposed in their stretch of the roadway or on parallel rails laid open by sleepers or the like and guiding the fixed pairs of wheels of the vehicle.
“Non-railbound vehicles” are conveyed along their stretch of the roadway and roadway sections or portions over a road and are driven along the roadway sections or portions by steering control equipment associated with the vehicle.
The present invention is based on and is intended to be used in the latter category and technology and is intended to be applied primarily to heavy trucks with or without connected trailers, wherein from U.S. Pat. No. 4,129,203-A a vehicle-related arrangement is known for letting contact springs disposed beneath the vehicle be brought upwards and downwards and sideways towards and to mechanical and electrical cooperation with or away from cooperation with non-insulated surface sections of the electric conductors (14) subject to voltage and associated with each roadway section or portion.
Utilizing an insulator (16) in a channel (18) which supports the conductors in the form of rails (14) is indicated here. A cover plate (20) provided with a slit (12) is removably attached to the upper and opposing wall portions of the channel (18), with this cover plate (20) being adjusted to a plane connecting to the upper surface (22) of the roadway section or portion.
FIGS. 2 and 3, respectively, in the mentioned Patent Publication describe a vehicle-related table (98), to which an arm (10) is rotatably attached (94, 96, 99). Sensors (30) allotted to the table (98) generate signals which with regard to their phase and magnitude indicate the direction to and distance from an axis (99) of rotation to a slit (12) in the cover plate (20), which is based on changes in a generated magnetic field.
The table (98) and arm (10) can be driven over a designated mechanism (31) by a motor (32) between predetermined limits and limit switches (40, 41) positioned there.
Patent publication WO 93/10995-A discloses an earlier known system for driving electrically controllable vehicles along a road and its roadway sections or portions.
FIG. 9 in the mentioned patent publication clarifies the basic structure of the system.
It is instructed here that the extension (14) of the roadway and its roadway portions are to be provided with electrically conductive road sections (300a-300f), wherein a roadway section may be considered to correspond to a roadway portion.
The vehicle (310) has an electric motor (320) and two (312, 314) or three (312, 312′ and 314, respectively) contact springs lying therebelow and being adapted for mechanical and electrical contact with the electrically conductive conductors, whose lengths are adapted to correspond to a chosen length (identically equal lengths) for utilized roadway sections or portions.
The electrically conductive conductors in the road sections (300a-399f) are disposed after each other with an intermediately oriented free space (302a-302e) so as thereby to prevent short-circuits in consequence of dragging contact springs (312, 312′, 314).
Every other road section (300b, 300d, 300f) is here connected continually to a reference voltage (ground potential), whereas the remaining road sections (300a, 300c, and 300e, respectively) are either directly connectable to a source (440) of DC-voltage or can be connected over a connecting means (304a, 304b, 304c) to any appropriate electric power source (308) when a vehicle is in the vicinity.
When an embodiment having three contact springs is to be utilized the distance between them is to be chosen such, that two or three contacts always are in electric contact with two road sections exhibiting opposite polarities and that neither of the two contacts is to be able to short-circuit the open space (302a-302e) between two adjacently positioned sections or portions.
For its function the system here requires specially structured vehicles (310), wherein the chosen distance between front (314) and rear (312, 312′) contacts is to be identical and furthermore to be chosen somewhat greater than the equal lengths of the roadway sections (300b, 300d).
Thus, specially structured vehicles with front and rear contacts are required and in which each one of the utilized road sections (300a-300f) is to be chosen having equal lengths and they are to be positioned behind each other in the direction of motion of the vehicle with equal mutual free and intermediately lying spaces (302a-302e).
The remainder of the Patent Publication shows the existence of a single conductor or rail subjected to voltage in a road section (Page 5, lines 11-13) and that a vehicle is to attract a voltage to a roadway section lying in front (Page 5, lines 19-21; page 6, lines 7-10; page 8, lines 28-32, respectively).
Furthermore it is indicated that bars or rails (16), which may be subjected to voltage, can be provided with side-positioned drainage tracks (page 9, lines 1-4).
Lack (or presence) of an activating signal is to be able to influence a control unit (38) (Page 8, lines 23-27, respectively).
The necessary distance between vehicle-associated contacts is disclosed in lines 17-20 of page 10, and utilizing activity-initiated radio signals is suggested in lines 2-4 of page 11 and lines 1-16 of page 14, respectively.
Furthermore, in lines 21-23 of page 15 and lines 1-15 of page 16, utilizing a Hall element (240) and connecting it to an amplifier (246) is suggested. Furthermore, alternatives thereof are illustrated in lines 3-9 of page 17.
It is also known to have a vehicle driven electrically along a stretch of roadway by means of inductive transfer of energy active between a vehicle and a roadway section and a road portion laying therebelow.
As examples of this known technology reference is also made to the contents of U.S. Pat. No. 3,914,562-A and U.S. Pat. No. 4,007,817-A, respectively.
Patent publication WO 2007/056 804 A1 describes and discloses a plurality of means, devices and/or arrangements, which have relevance when evaluating the significant features related to the prior art and also to the present invention. However, these means, devices and/or arrangements are only mentioned in general terms, and only a few or no suggested structure is disclosed.
The contents of this patent publication will be described in the following and coordinated in the following subsections;                a. Pairs of electrically conductive contacts or strips oriented along a roadway.        b. Switching means to supply DC power to a roadway related pair of electrically conductive contacts or strips. (DC network).        c. Vehicle related transmitter.        d. Vehicle related pick-up arms.        e. DC-voltage difference between roadway related conductors, contacts or strips.        f. Orientation of the roadway related conductive strips.        g. Power supply system.        h. Detector means or arrangement.        i. Power supply to an adjacent pair of conducting strips.        j. Sensor arrangement.        k. Conditions for activating switching means.        l. Battery arrangements.        m. On-board charging engine.        n. Overload cut-off and re-close switch.        o. Safe conditions of bare electric roadway related electric conductors or strips.        p. Use of DC voltage or AC voltage to supply power to the roadway related electric conductors or strips.        q. Magnetic field sensor.        r. Snow plough and blower arrangements.        s. Electrical heating tape.a. Pairs of Electrically Conductive Conductors or Strips Oriented Along a Roadway.        
It is suggested in the above-mentioned International Patent Publication that each pair of electrically conductive strips (members) be electrically insulated from an adjacent and another pair of electrically conductive strips, and wherein a vehicle traveling along said roadway travels over a first pair of electrically conductive strips and then travels over a next adjacent pair of electrically conductive strips and so forth.
b. Switching Means to Supply DC Power to a Roadway Related Pair of Electrically Conductive Contacts or Strips (DC-Network).
A source of direct current electricity (DC-network) is arranged to provide a DC power to the roadway related pairs of electrically conductive strips (members).
Switching means are operative to supply DC power to a pair of electrically conductive strips when a vehicle travels over that pair, said switching means being operative to turn off the supply of DC power to a pair of electrically conductive strips when no vehicle travels over and along that pair of electrically conductive strips.
This improves the safety of the system as suggested (page 2, lines 13-17) in that switching means are operative to supply DC power to said pair of electrically conductive strips (members) only when a vehicle travels over that pair, the switching means being operative to turn off the supply of DC power to a pair of electrically conductive strips when no vehicle travels over that pair of electrically conductive strips.
Said Patent Publication further mentions (page 1, lines 7-21) a prior art system for the universal use of electrically powered roadway vehicles. A system of this kind uses a succession of 20 meter long copper strips fixed onto a roadway surface. The respective 20 meter long copper strips were positioned end to end along each lane of the roadway and were electrically insulated from each other.
Alternating current electric power (AC-network) was applied to each section or portion.
c. Vehicle-Related Transmitter.
When an appropriate electrically powered vehicle travels over the respective sections of copper strip, a transmitter, mounted to the vehicle, turns on the power supply to that section of copper strips on which the vehicle is traveling.
d. Vehicle Related Pick-Up Arms.
Electrically operated pick-up arms on the vehicle are adapted to contact the copper strips and to obtain electricity from the roadway-related copper strips.
This electricity from the copper strips is used to run a vehicle-related electric motor on board the vehicle (and also to activate vehicle accessories and, optionally, to recharge batteries on the vehicle).
The electricity supply to each copper strip is only turned on during 1.5 seconds, i.e. the time period during which the vehicle passes over that section of copper strips.
In the absence of a signal from a vehicle, the power to that section of copper strip remains off.
In order for the vehicle to be able to pick up electric power from the roadway-related conductors or strips positioned on the roadway surface, the vehicle may be provided with a pick-up arm located under the vehicle body.
The pick-up arm may comprise a flat plate hinged to the underside of the vehicle.
Two pick-up carbon brushes may be bonded to the plate, for example by an epoxy resin or adhesive.
Leads carry the power from/to each brush to the vehicle (to the motor controller and battery pack of the vehicle). (Page 7, lines 8-13)
The pick-up arm may be retracted and extended automatically.
For example, if the vehicle detects that it is traveling over a pair of electrically conductive strips (members), the pick-up arm may be automatically extended downwardly such that the brushes contact the electrically conductive strips.
In one embodiment, the electrically conductive arm is operated such, that if power is lost for more than a predetermined time period, such as from one-half to one second, the pick-up arm is automatically retracted. (Page 7, lines 14-19)
Vehicles traveling over the pairs of copper strips must be able to pick up electric power from those strips.
A large number of different designs may be used in this regard. However, one possible design is shown with reference to FIG. 2.
In FIG. 2 a vehicle 50, having wheels 52, 54, is provided with a plate 56. Plate 56 may for example be approximately 1.620 mm wide and 100 mm long.
The plate 56, as shown in FIG. 2, stretches approximately across the full width of the vehicle.
The plate 56 may be provided with one or more holes to enable air to pass therethrough to reduce the amount of down force acting on the plate when the vehicle is traveling.
The plate 56 carries two electrically conductive brushes 58, 60.
A gap 62 is located between the brushes 58, 60.
As an example, each brush may be 800 mm wide and the gap may be 20 mm wide.
The gap 62 may be filled with an electrically insulating material, suitably an insulating material that is somewhat soft and can yield without breaking, should it contact an object. (Page 14, lines 7-18).
The use of a wide pick-up plate eliminates the need for a lateral traversing mechanism for the pick-up arm.
It also eliminates the need for any device to detect the vehicle's lateral position in relation to the electrically conductive strips.
All a driver has to do to achieve initial contact is to drive along the electrically conductive strips somewhere within the vehicle's track and move the pick-up arm to the down position.
Contact will be maintained so long as the electrically conductive strips remain within the vehicle track.
Automatic steering may be used to assist in this regard on a longer drive. (Page 14, lines 27-30, page 15, lines 1-2)
The brushes 58, 60 must be able to be lowered onto the strips or retracted against the underside of the vehicle.
To this end, the brushes are mounted on a pair of pantograph arms 64, 66.
The pantograph arms keep the plate 56 (and therefore the brushes 58, 60) horizontal.
Appropriate electrical connections may be provided to enable the electrical power picked up from each of the brushes 58, 60 to be transferred to the vehicle.
The pantograph arms may carry appropriate electrical cables to transfer electric power from the brushes to the vehicle. (Page 15, lines 4-10)
e. DC-Voltage Difference Between Roadway Related Conductors, Contacts or Strips.
It is further suggested (page 2, lines 18-22) that preferably DC power with its voltage exposes a difference between each conductor or strip in a pair of conductors and that said voltage does not exceed 600 volts. More preferably, the DC power and its voltage difference between each conductor in a pair of conductors or strips do not exceed about 450 volts. Suitably, each conductor is at a voltage relevant to earth that does not exceed plus or minus 250 volts, more preferably not exceeding plus or minus 225 volts.
f. Orientation of the Roadway Related Conductive Strips.
The electrically conductive strips may be positioned on the roadway surface such that they are insulated from each other and from earth (the road surface). Suitably, the electrically conductive strips are laid onto an adhesive insulating base, which insulates them from each other.
The electrically conductive strips may be bonded to the roadway surface by an epoxy adhesive. Alternatively, the electrically conductive strips may be bonded to tiles that are then placed in or on the roadway surface.
g. Power Supply System.
The power supply system comprises a series of separate, electrically insulated but electrically conductive strips.
Each pair of strips represents a power supply section.
Each pair of strips may be provided with a dedicated source of DC power.
Alternatively, a source of DC power may provide direct current electricity to two or more pairs of strips.
h. Detector Means or Arrangement.
The switching means is suitably operatively associated with a detector means for detecting the presence of a vehicle, either about to move onto a pair of conductors or strips or on a pair of conductors.
For example, the coded signal may comprise an oscillating voltage similar to that used by utility companies for control purposes.
Such a control signal may have a frequency in the order of 400 kHz and a voltage of up to about 4 to 20 volts.
It will be understood that the coded signal may utilize different frequencies and different voltages from those given above. (Page 4, lines 19-29)
When one roadway section of conductors or strips is turned on, a control signal may be sent to the power supply for the next section of conductors along the path of travel of the vehicle.
This control signal, sent to the power source for the next section of conductors or strips, is used to turn on the power supply to the next section of conductors, either shortly before or just as the vehicle arrives at the next section of conductors.
Alternatively, the control signal sent to the next section of conductors or strips may turn on the power supply to that next section of conductors at a predetermined time after the power supply to the first set of conductors or strips is activated.
In order to detect the arrival or imminent arrival of a vehicle in a section of copper strips, the vehicle may be provided with a coded signal that becomes superimposed on the strips when the vehicle travels over a section or portion of the copper strips and the brushes on the vehicle are in contact with the strips.
The coded signal is received by a detector associated with a corresponding transformer station.
The detector actuates the switching of power up to that particular section of the strips.
i. Power Supply to an Adjacent Pair of Conductive Strips.
The power supply to the next set of conductor means or strips is maintained, provided that the next set of conductors or strips detects that the vehicle enters the next set of conductors or strips within a specified time period after the power supply to the next set of conductors or strips has been turned on.
In this way, if the vehicle turns off the roadway and therefore does not enter the next set of conductors or strips, the next set of conductors or strips will not detect the presence of the vehicle and therefore will shut off the power supply shortly after it has been turned on.
In this embodiment, the adjacent sections of conductors “talk” to each other and interact with each other to turn on the power supply to each roadway section with its strips either just before or just as a vehicle arrives at each section.
j. Sensor Arrangement.
A sensor arrangement may be located towards the “downstream” end of each pair of strips.
The sensor arrangement may, for example, be a current flow sensor positioned below or adjacent to one of the electrically conductive strips.
When a vehicle is near the end of a roadway section (of electrically conductive strips), the sensor will sense the resultant current flow and then send a signal to the next section of electrically conductive strips to turn on the electricity supply to the next section in “anticipation” of the imminent arrival.
This signal may be sent via cable. The “anticipatory” signal is valid for a short time only, say 2 seconds, and if a vehicle has not arrived at the next section within that time, the next section is turned off.
k. Conditions for Activating Switching Means.
The switching means may be arranged such that the signal that is used to turn on the next pair of conductive strips must be larger than a predetermined minimum value in order to activate the switching means and turn on the next pair of conductive strips.
In this manner, if the next pair of conductive strips is subject to conditions of high electrical leakage, the signal will be lower than the minimum required to turn on the next pair of strips.
This is effective to minimize excessive electrical leakage which could lead to unacceptable power wastage and/or to damage to the transformer/rectifier. (Page 4, lines 28-29, page 5, lines 1-4).
The use of a coded signal also allows for the possibility of enhanced operation and safety by incorporating an electricity leakage test into the apparatus.
In these instances, an electrical leakage detection means may be provided to prevent the next section of conductors or strips from turning on.
Detection of electrical leakage may occur by requiring the coded signal superimposed on each section of conductors or strips to exceed a predetermined activation threshold value before the next section of conductors or strips will be turned on.
In this fashion, superimposing the coded signal onto the conductors or strips will result in the coded signal representing the criteria not exceeding the predetermined threshold value if conditions of high electric leakage are present. Thus, the next section of conductors or strips will not be turned on in such situations. (Page 8, lines 15-28)
l. Battery Arrangements.
The vehicle may be provided with one or more batteries to store electric power or energy.
The batteries may be charged using electricity received from the roadway related electrically conductive strips.
In some embodiments, the DC voltage of the electrically conductive strips is such that it is equal to the normal charging voltage of each battery pack in the vehicle.
This allows for the vehicle motor to have an essentially seamless transition to and from battery and on-road conductors or strips whenever there is a break and then a resumption of the on-road conductors or strips. (Page 6, lines 29-30, page 7, lines 1-5)
m. On-Board Charging Engine.
The vehicle may alternatively or additionally be provided with one or more of an on-board charging engine or a regenerative braking system to allow for recharging of the batteries. (Page 7, lines 6-7)
n. Overload Cut-Out and Re-Close Switch.
Each transformer may have an overload cut-out and re-close switch.
This switch suitably operates on the DC side of the transformer and a rectifier. Each DC output line from the transformer and rectifiers may have independent overload switches.
The overload cut-out and re-close switches may be set such, that if three re-close attempts are unsuccessfully made the section is shut down and a signal is automatically sent to the control panel to indicate a fault.
Vehicles may then proceed across this dead section using an on-board battery power system. (Page 12, lines 10-16)
o. Safe Conditions of Bare Electric Roadway Related Electric Conductors or Strips.
A question may be raised as to whether bare electric conductors or strips on a road surface can be safe. In the system here proposed, they are safe.
In particular, the present invention uses mains power but delivers DC voltage at relatively low volts.
Moreover, each copper conductor or strip is insulated from the roadway surface and from the other copper conductor or strip in its respective pair.
Thus, standing on one of the conductors or strips will not complete any circuit and therefore little or no current will flow through a person standing on one of the copper conductors or strips.
Further, the DC voltage supply to the conductors or strips is created by transforming and rectifying high voltage, three-phase (alternating current) AC-power, to give a positive DC-power to one conductor or strip and an equal negative DC-power to the other conductor or strip in each pair of conductors or strips. (Page 12, lines 19-20)
p. Use of DC Voltage or AC Voltage to Supply Power to the Roadway Related Electric Conductors or Strips.
The use of DC voltage rather than AC voltage contributes to the electrical safety of the system.
The actual DC voltage that is supplied to the pairs of copper conductors or strips will depend upon several factors.
For example, the lower the standard DC voltage selected, the lower will be the perceived electrical safety risk, the lower will be the actual energy leakage, when a roadway is wet and the conductors or strips are on, and the fewer the number of battery cells in each vehicle to provide an on-board power supply.
On the other hand, the weight of copper conductors or strips and/or the number of transformers needed for the on-road installation is inversely proportional to the square of the standard voltage.
That is to say, other things being equal, if the voltage is halved, the weight and cost of copper material needed will rise fourfold.
It has been found that possible standard voltages may lie anywhere between about 100 and 600 DC voltage. (Page 12, lines 3-12)
q. Magnetic Field Sensor.
An array of magnetic field sensors may be placed across the front and rear of the vehicle (page 20, lines 3-9) to sense the position of the conductive strips.
r. Snow Ploughs and Blower Arrangements.
The use of snow ploughs and blower arrangements is also suggested. (Page 21, lines 28-30.)
s. Electrical Heating Tape.
It is also suggested to use an electrical heating tape beside each conductor or strip to aid the clean removal of snow and ice in winter time. (Page 22, lines 1-3.)
This invention intends to concentrate on a vehicle-related arrangement, for actuating upwards and downwards and sideways a means cleaning or cleansing the track (groove) or tracks (grooves) from loose and/or solid particles along the stretch of a roadway, such as in the form of a contact means or a current collector intended for cooperation with electric conductors with contact surfaces, which may be placed under electric voltage and are disposed along individual tracks, wherein such cleansing means is/are to be able to be displaced when the vehicle and its contact means is driven forward and, as a suggestion, are to be disposed, counted in the direction of movement, as a unit in front of or as a contact means, shaped as a current collector.